Hi h9px732v,
Thanks for your message, and welcome to deSEC! 
We are planning to re-enable registrations under .dedyn.io at the end of this year or early next year.
With the re-enabled service, it will not be possible to change the domain’s NS records. Domains under .dedyn.io will be required to be hosted at deSEC.
(This was already the case previously. However, during the issue in the beginning of the year, most of the problematic registrations seemed to be attempting to mess with NS records – so we will block such changes, and are hoping to prevent the associated problems from returning.)
Stay secure,
Peter